In a principal aspect, the present invention relates to a tool for removing nuts, bolts and/or studs from a work piece where the threads have been stripped, the heads have been damaged or other circumstances necessitate to use a special tool to effect removal. The invention also relates to a set of such tools, which may be used with a multiplicity of sizes of nuts, bolts and/or studs.
Often, mechanics and other skilled trades persons are faced with the need to disassemble machinery, engines or the like. When engaging in such tasks, it may be necessary to remove nuts, bolts, headed fasteners, studs and the like. Attempts at such removal may result in the stripping of the threads or head or the breaking of such a bolt or stud. For example, a bolt may have a head which enjoys a polygonal shape but that is malformed or deformed. The same may be true with respect to a threaded stud or nut. Thus, there has developed a need for tools which will facilitate removal of nuts, bolts and/or studs which have been damaged, deformed or otherwise rendered incapable of easy removal from a work piece using conventional wrenches and equivalent tools.
Various solutions have been proposed to effect removal of such bolts and studs. For example, numerous patents have issued over the years depicting tools to facilitate such removal. Included among those are McGuckin, U.S. Pat. No. 1,590,200; Hildebrand, U.S. Pat. No. 5,737,981; Horobec, U.S. Pat. No. 5,551,320; Spirer, U.S. Pat. No. 5,907,983; Siwy, U.S. Pat. No. 5,904,076; Knox et al., U.S. Pat. No. 6,003,411 and Hanson, U.S. Pat. No. 4,671,141.
Typically, tools of this nature include a bore or counterbore with various types of teeth formed inside the bore. The teeth engage over the head of a deformed bolt or over a stud, and upon rotation of the tool, the teeth grip into the stud or bolt thereby facilitating removal. Often the teeth in such tools are canted or inclined in one direction or the other to facilitate the gripping action. Of course, if the gripping action is facilitated for turning of the tool in a first sense or direction because of the canted teeth, the result of turning in the opposite direction is that the gripping is not as effective.
In most instances, tools of this nature are also very difficult to manufacture. That is, the pattern of teeth or gripping ribs or members provided in the bore of such tools is quite difficult to form particularly if the shape is complex and if the teeth are inclined in one direction or the other. As a consequence, there has remained and continues to be the need to provide a bolt and stud removal tool which is useful for both studs as well as bolts, which has application over a wide range of bolt and stud sizes, which will not strip the bolt or stud, and which may be used by rotation in any sense or direction, which is economical and otherwise easy to use.
Briefly, the present invention comprises a bolt and stud removal tool, as well as a set of such tools wherein members of the set comprise an elongate body member, symmetrical about a centerline axis with a bore or counterbore extending axially through or into the tool, said bore or counterbore including at least three internal ribs or teeth formed and arranged in an array about the axis within the bore or counterbore. The teeth each have a particular configuration; namely, the teeth are each formed of first and second side walls converging toward the axis parallel to the centerline axis and a third wall connecting the first and second walls, the third wall also being parallel to the centerline axis spaced radially from the centerline axis. Planar projections of the first and second converging walls intersect intermediate the centerline axis and the connecting third wall. Consequently, a cross-sectional profile of each of the ribs or teeth has a truncated shape with the narrow end of the truncated form facing or adjacent the centerline axis of the bore through the tool and the wide or base portion of the truncated rib or tooth spaced radially outward from the internal, connecting third wall.
The stud and bold removal tools are typically provided as a set having a series of sizes to accommodate multiple sizes of bolts and other fasteners. Each tool, preferably, includes a counterbore recess at its operative end (the end fitting over a bold or stud) to facilitate working alignment of the tool on a stud or bolt. Preferable, each tool further includes a shard gathering and retaining or receiving section distal from the operative end but adjacent to the section or part of the tool which comprises the teeth or ribs in the bore. The shard section is for receiving and holding shards that are formed during use of the tool. Preferably, the tool includes a polygonal outside surface, for example, a hexagonal shape which enables gripping and use of the tool by means of another tool such as a wrench or the like. In a preferred embodiment, six equally spaced inwardly extending ribs or teeth having the same size and shape and lying with their base on the same cylinder and of the nature described are provided for the tool. Also in a preferred embodiment, the tool includes a throughbore rather than merely a counterbore so that the end of a stud to be removed may fit entirely through the tool if necessary.
Thus, it is an object of the invention to provide an improved bolt and stud removal tool.
It is a further object of the invention to provide an improved bolt and stud removal set of tools designed for utilization with variously sized bolts and studs.
Yet another object of the invention is to provide a bolt and stud removal tool which may be rotated in either sense once positioned on a bolt or stud and having equal utility and effectiveness regardless of the sense of rotation of the tool to remove a nut, bolt or stud.
Yet another object of the invention is to provide a bolt and stud removal tool which is easy to use, and which does not tend to strip or further destroy the stud or bolt upon which it is to be used, but rather which provides a maximum torque to effect removal of the stud or bolt.
Another object of the invention is to provide a bolt and stud removal tool which may be easily manufactured utilizing conventional manufacturing techniques.
These and other objects, advantages and features of the invention will be set forth in the detailed description which follows.